The present invention relates to a magnetic disk drive, and more particularly to a clamp for fixing a magnetic disk to a motor hub.
In a magnetic disk drive such as a hard disk drive, the magnetic disk to which data is written is fixed to the motor hub.
One conventional method for attaching the magnetic disk to the motor hub includes the steps of placing the magnetic disk on the disk support portion of the motor hub, placing a disk-spring-shaped metal clamp on the magnetic disk, and fixing the clamp to the motor hub with a screw(s) to hold the magnetic disk between the clamp and the disk support portion. See, e.g., Patent Document 1 (Japanese Patent Laid-Open No. 2001-148187).
Another conventional method for attaching the magnetic disk to the motor hub is to shrinkage fit the clamp onto the motor hub without using screws. See, e.g., Patent Document 2 (Japanese Patent Laid-Open No. 08-297944 (1996)). Specifically, according to this method, after placing the magnetic disk on the disk support portion of the motor hub, a ring-shaped metal clamp is placed on the disk such that the clamp is engaged with the outer circumference of the motor hub. When the ring-shaped metal clamp is placed on the magnetic disk, thermal energy is applied to the clamp such that the inside diameter of the clamp becomes larger than the outside diameter of the motor hub due to the thermal distortion of the clamp. After that, the ring-shaped clamp is cooled, causing the clamp to shrink. As a result, the clamp clamps the motor hub, and hence the magnetic disk is fixed between the clamp and the disk receiving surface of the motor hub.